For more than a decade, photonic band-gap (PBG) structures have received a great deal of attention due to their ability to control the propagation of light as disclosed in E. Yablonovitch, Phys. Rev. Lett. 58, 2059 (1987); S. John, Phys. Rev. Lett. 58, 2486 (1987), which is herein incorporated by reference in its entirety. A photonic band-gap device is a macroscopic, periodic dielectric structure that possesses spectral gaps (stop bands) for electromagnetic waves, in analogy with the energy bands and gaps in regular semiconductors. PBG materials possess a periodic dielectric function that creates a range of wavelengths in which light cannot travel. Inserting a defect into the PBG structure breaks the periodicity of the dielectric function and introduces a passband into the transmission spectrum. Fabrication of PBG filters, mirrors, waveguides and lasers has already been demonstrated and these devices are expected to enhance performance in optoelectronic and telecommunications applications as disclosed in A. Birner, R. B. Wehrspohn, U. Gösele, K. Busch, Adv. Mater. 13, 377 (2001); S. Y. Lin, E. Chow, S. G. Johnson, J. D. Joannopoulos, Opt. Lett. 25, 1297 (2000); O. Painter, R. K. Lee, A. Scherer, A. Yariv, J. D. O'Brien, P. D. Dapkus, I. Kim, Science 284, 1819 (1999), which are herein incorporated by reference in their entirety. Among the different materials used to prepare such structures, porous silicon (PSi) is very promising due to its low cost, compatibility with microelectronic technology as disclosed in K. D. Hirschman, L. Tsybeskov, S. P. Duttagupta, and P. M. Fauchet, Nature 384, 338 (1996), which is herein incorporated by reference in its entirety, and ability to modulate its refractive index as a function of depth as disclosed in C. C. Striemer and P. M. Fauchet, Appl. Phys. Lett. 81, 2980 (2002), which is herein incorporated by reference in its entirety. Silicon-based PBG devices could have a significant impact as optical interconnects and switches in the next generation of microelectronic technology as disclosed in A. Birner, R. B. Wehrspohn, U. Gösele, K. Busch, Adv. Mater. 13, 377 (2001) and N. Savage, IEEE Spectrum 39, 32 (2002) which are herein incorporated by reference in their entirety. However, before direct applications appear, some key issues remain to be resolved. In particular, as PBG technology matures, temperature stability needs to be addressed as disclosed in P. T. Lee, J. R. Cao, S. J. Choi, Z. J. Wei, J. D. O'Brien, P. D. Dapkus, Appl. Phys. Lett. 81, 3311 (2002), which is herein incorporated by reference in its entirety. It is critical to the operation of PBG devices that the wavelengths of the forbidden band do not drift when the device is exposed to a variable temperature range. Such a drift could cease the flow of light in the structure.
For example, in PSi microcavities, the position of the reflectance resonance is highly sensitive to changes in the refractive index. Since the refractive index of silicon is temperature dependent, even a small change in temperature could alter light confinement in the PBG. For silicon-based microcavities with very narrow line widths (i.e., ˜1 nm) as disclosed in P. J. Reece, G. Lerondel, W. H. Zheng, and M. Gal, Appl. Phys. Lett. 81, 4895 (2002), which is herein incorporated by reference in its entirety, this temperature sensitivity becomes even more critical. The operation of an optical switch based on such a structure could change from an off-state to an on-state with small fluctuations in temperature.